DESCRIPTION: Aims: 1) To determine whether the continuously uninsured (?92-?98) are at increased risk of developing a major decline in overall health and/or a new physical difficulty from ?92-?00, and whether the relative risks for these outcomes change over time. 2) To determine whether people who are intermittently uninsured are at increased risk of these same adverse outcomes for a) periods during which they were uninsured (i.e., concurrent effects), and b) periods after an episode without insurance (i.e., lagged effects from having been uninsured). 3) To determine whether individuals who were uninsured > 1 times from ?92-?98 were at increased risk of a) death and b) death/major decline in health. 4) To determine the degree to which lower rates of insurance explain socioeconomic and racial/ethnic differences in health outcomes. Methods: This project will conduct a series of prospective cohort studies using data files from the Health and Retirement study, which consists of a national sample of US adults 51-61 years old beginning in 1992 with follow-up interviews every 2 years. Deaths were determined through contacts and the National Death Index. Insurance coverage (private or public), health status, socioeconomic status, chronic diseases, and health behaviors will be determined at the time of each interview. Health outcomes will include 1) a major decline in overall health, defined as either a decline from excellent, very good, or good health at time 1 to fair or poor health at time 2, or a decline from fair health to poor health; 2) development of a new difficulty walking or climbing stairs (mobility) or a new difficulty with activities of daily living; 3) death. Based on, insurance coverage, we will construct cohorts of individuals who were continuously insured (private or public), continuously uninsured, lost insurance (transitioned from insured to uninsured), and gained insurance. Multivariate logistic regression and Cox proportional hazards survival analyses will be used to examine the relationship between patterns of insurance coverage and the risk of adverse health outcomes. Significance: This will be the first study to assess whether being uninsured has only contemporaneous adverse effects or whether lack of insurance has cumulative and lagged effects. Many Americans are intermittently uninsured. If this group has an increased risk of adverse outcomes, this would suggest that we monitor the number of people who are continuously or intermittently uninsured to estimate the number of Americans vulnerable to the effects of being uninsured.